Coxsackievirus B3 Infection Induces cyr61 Activation via JNK To Mediate Cell Death

Abstract

Coxsackievirus B3 (CVB3), an enterovirus in the Picornavirus family, is the most common human pathogen associated with myocarditis and idiopathic dilated cardiomyopathy. We found upregulation of the cysteine-rich protein gene (cyr61) after CVB3 infection in HeLa cells with a cDNA microarray approach, which is confirmed by Northern blot analysis. It is also revealed that the extracellular amount of Cyr61 protein was increased after CVB3 infection in HeLa cells. cyr61 is an early-transcribed gene, and the Cyr61 protein is secreted into the extracellular matrix. Its function is related to cell adhesion, migration, and neuronal cell death. Here, we show that activation of the cyr61 promoter by CVB3 infection is dependent on JNK activation induced by CVB3 replication and viral protein expression in infected cells. To explore the role of Cyr61 protein in infected HeLa cells, we transiently overexpressed cyr61 and infected HeLa cells with CVB3. This increased CVB3 growth in the cells and promoted host cell death by viral infection, whereas down-expression of cyr61 with short interfering RNA reduced CVB3 growth and showed resistance to cell death by CVB3 infection. In conclusion, we have demonstrated a new role for cyr61 in HeLa cells infected with CVB3, which is associated with the cell death induced by virus infection. These data thus expand our understanding of the physiological functions of cyr61 in virus-induced cell death and provide new insights into the cellular factors involved.

Uses for JNK: the Many and Varied Substrates of the c-Jun N-Terminal Kinases

“…There is also an increasing body of literature showing that JNK activation follows bacterial, fungal, prion, parasitic, or viral infections. Under these circumstances, JNK activation may influence important cellular consequences, such as alterations in gene expression (1,53,59,162,167,176,199,294,325,326,346), cell death (58,89,137,139,169,193,243,293), viral replication, persistent infection or progeny release (215,224,251,260), or altered cellular proliferation (178). The exact mechanism of JNK activation under each of these circumstances remains to be elucidated fully, although there may be involvement of Toll-like receptors, direct pathway modulation through interaction with upstream protein regulators, or the activation following an ER stress response (79,87,110,124,143,191,253,261,279,294,312).…”

Profiling Subcellular Protein Phosphatase Responses to Coxsackievirus B3 Infection of Cardiomyocytes

“…ERK2 phosphatase activity likely reflected the compensatory up-regulation of cytoplasmic DUSPs, such as MKP3, that could be induced by CVB3 activation of the ERK pathway (37). The NE-associated JNK1 phosphatase result was more intriguing given conflicting reports involving the role of JNK activation in CVB3 pathogenesis (38,111). We therefore pursued follow-on experiments to dissect mechanistically the role of CVB3-associated JNK1 phosphatase activity in the NE fraction.…”

“…Prior CVB3 studies involving the JNK pathway relied on a first-generation inhibitor that is now known to inhibit many other kinases (38,111,112). We therefore turned to JNK-IN-8 (IN8), a newer covalent JNK inhibitor that is much more selective (113).…”

Coxsackievirus B3 used as a gene therapy vector to express functional FGF2

“…31 The wild-type CVB3, an H3 Woodruff variant strain (donated by Prof. E Jeon, Samsung Medical Center, Seoul, Korea), 32 was grown and titered in HeLa cells. In this paper, 'CVB3' means wild-type CVB3.…”